Ground Combat - Need help

[Kaiser (OP)]

Hi guys, I need your help to conquer an alien planet.
I understood the ground combat mechanics at very basica level, it is my first ground combat ever in Aurora, there are still a lot of obscure points.
I want conquer the planet intact, so I am not using orbital bombardment or something, I have already sent a lot of ground units, but I destroyed only about 200 elements while I lost thousand and thousand.

According the intelligence, the enemy seems to have:
1242 Centurion
104 Praetorian Combat Mech
58 Decurion AA Mech
13 Construction Vehicle
30 Artilley
6 Praetorian Leader
12 STO
8 STO-PD
100 resupply infantry
157 resupply vehicle.

I can provide you with the specific for each element if It can be useful, however they are a mix of medium vehicle and infantry, I suspect the Mech are the strongest here.

I have developed most of the ground tech and researched tank, artillery and infantry but I can't destroy the enemy.
I have at my disposal, 6 Assault ships, with 10000t orbital drop ground unit each, so I can transport 60000t to the enemy planet.

How would you procede? How would you organize your forces?

[Garfunkel]

Is their weapon tech higher than your armour tech? Is your weapon tech higher than their armour tech? That has a significant impact on force composition.

[Cobaia]

Maybe some info in this post can help:
http://aurora2.pentarch.org/index.php?topic=11691

[Black]

You also need to check the planetary terrain, I once wanted to dislodge Precursor forces from venusian mountainous world, that was very painful. You want specialized troops if there are some terrain or other modifiers in play. They are also most likely fortified, so you have lesser chance to hit them. Also the reported numbers are most likely lower that the reality. There may be twice that is reported.

You need to keep an eye on your supplies if your units are low on supplies you are screwed.

I usually deploy around 250000 tons of mixed troops to deal with Precursor outposts and some of my formations still get quite mauled. That is with technologies with cost around 30k points.